Arc welding



Feb. 26, 1924. 1,485,120

J. F. LINCOLN ARC WELDING Filed June 23. 1922' INVENTOR.

ATTORNE J Patented F eb. 26,1924.

UNITED STATES v 1,485,120 PATENT OFFICE.

IAIES I. LINCOLN, OF EAST CLEVELAND, OH IO, ASSIGNOB TO THE LINCOLN ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ABC WELDING.

Application filed June as, 1922. Serial No. 570,449.

To all whom it may concern:

Be it known that I, JAMES F. LINCOLN, a citizenof the United States, and a resident of East Cleveland, county of Guyahoga, and State of Ohio, have invented a new and useful Improvement in Arc Welding, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I havecontemplated applying that principle, so as to distinguish it from other inventions.

In the more or less familiar method of electrically welding together metal parts, and particularly metal sheets, by bringing the edges of such parts 'or sheets together and striking an are between the same and an electrode that is moved along the seam or joint, considerable diiiiculty is encountered in securing a smooth, even )UHGiZUlQ or weld. VV-hen the electrode in question is initially brought suiiicicntly close to the work to cause an arc to form, the'adjacent edges will be fused hy the heating of the arc and a small pool oi molten metal results.

When an arc is thus established, in the iirst'place the vapor coming oil will allow the arc to travel through it a great deal more readily than through air; and, in the second place on account of the metal heconr heated with the to ation of a incl an me tends he atter digs other ong the work, the arc will .i to the spot on the work where such are is first formed until it becomes sufliciently attenuated, whereupon it will establish itself between the moving electrode and the nearest point along the path of movement, which may be some little distance in advance of the first point just referred to. There will accordingly he an intermediate section that is not properly fused, the finishedseam presenting the effect of a series of more or less disconnected welds instead of one continuous weld of uniform depth and strength.

The object of the present improved method or rocess, accordin 1y, is to overcome the di culty just note which I have discovered is possible by a relativel simple manipulation consisting principal y in a proper inclination of the seam or line of the weld. To the accom lishment of the foregoing and related en s, the invention, then, consists of the steps hereinafter fully described and particularly pointed out in the claims, the annexed drawin and the fol lowlng description setting orth in detail one approved method of carrying out the invention, such disclosed mode, however, constituting, but one of the various ways in which the principle of the invention maybe used.

In said annexed drawing Fig. 1 is a more or less diagrammatic re resentation of the manner in which a we d is formed Where an electric arc is used in accordance with the prevailing practice; Fig. 2 illustrates an arc welding operation Where conducted in accordance with my present improved method or process; and Fig. 3 similarly represents the adaptation of such method or process to a different operative condition than that shown in 2;

In each of the foregoing figures it wili be noted that only the electrode 1. and the metal article 2 which is to be welded shown. Such electrode will ordinarily be carbon pencii and will be connected wit one side, preferahiy the negative, of su source of current, the other s '2 er connected with the work grainmatic representation of means for .pporting either as T8 the electrode, or for producing the :ee relative movement therehetween, 5'... since for the purpose in hand. it may sinned that the eiectrcde is simply mover manually along the line of the weld... In each of the figures the work 2 is as sectioned on a plane passing centre through such line, such work being show life;

as a straight piece in Figs. 1 and 2 and as illustrates the current practice in arc weld- I ing, the electrode is'held at a slight angle to the vertical, inclining in thedirection in which it is moved relatively to the work, such direction being indicated by the arrow both in this figure and in Fig. 2. Assuming thework to be disposed substantially horizontally, the are 3 that is established between the lower end of the electrode and the work will, as previously stated, promptly form a small pool 4 of molten metal and the arc tends to cling or stick temporarily to such spot, despite the ad vance movement of the electrode. Accordingly, when the arc does shift it will jump a trifle and the intermediate section of the seam or joint will not be so thoroughl welded; indeed it may not be welded at a the result being that a series of welds 5 is produced instead of a continuous weld of uniform depth and strength.

I have found, however, that if the work 2 be tilted or inclined, so that the line of the seam or joint to be welded slants downwardly from the horizontal in the direction in which the electrode 1 is moved, the influence of gravity on the molten pool of metal formed where the arc is first struck will cause the same to tend to travel more nearly in unison with the travel of the electrode. Under these conditions, in other words, gravity will counteract the tendency of the arc to dig a hole through the metal and the arc is caused to bite into the metal in front of it rather than stay in the same place where it has begun its work. The are 3 accordingly is neverunduly strained or caused to jump but remains more nearly constant in length and in heating effect. The result hence is the production of a weld 6 that is of uniform depth and character otherwise, as shown in Fig. 2.

The angle at which the work should be inclined in order to produce this desirable result will vary with difierent metals and also is dependent upon the depth of the weld desired, i. e., the penetration of the heating efiect of the are below the upper surface of the work, as well as u on the character of the joint or seam. owever, the proper angle of inclination for any particular operation can be readil ascertained,

the test being the avoidance o the tendency of the arc to jump in the fashion described above.

Where in place of the joint or seam being rectilinear, or lying in the same plane, such joint extends circularly around a cylindrical bod for example, as in the operation of wel ing the end ring 7 of a rotor to a rotor winding, consisting of round rods or bars 8, the result just described is obtained by holding the electrode just over the highest point of the ring on the unfinished side having regard to the direction in which the ring is rotated as the weldin operation proceeds (see Fig. 3). In suc case, in other words, it is more convenient .to move the work past the electrode than to move the latter around the work and this in fact is essential if a uniformly good weld is to be obtained in accordance with the present improved procedure. At the particular point where the are from the electrode 1 0 rates on the metal it will be seen that tli line of the seam or joint inclines at approximately the same angle as does the rectilinearly extending line in Fig. 2. There is accordingly present the same tendency, whether due to ravity or other influence, for the metal as it becomes molten to maintain a constant position with respect to the end of the electrode and thus avoid stretching the are until the latter is caused to jump.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the method herein disclosed, provided the step or steps stated b any of the following claims or the equiva ent of such stated ste or steps be employed.

I there ore particularly point out and distinctl claim as my invention 1. 11 metal working by electricity, the steps which consist in establishing an are between the work and a suitable electrode, relatively moving such work and electrode to cause the latter to follow the line to be welded, and at the same time so positioning such work and electrode that the portion of the line in question under the arc inclines downwardly in the direction of travel oi. the electrode relatively to the work.

2. In metal working by electricity, the steps which consist in establishing an are between the work and a suitable elect-rode, relatively moving such work and electrode to cause the latter to follow the line to be welded, and at the same time tilting the work so that the portion of the line in question under the arc inclines downwardly in the direction of travel of the electrode relatively to the work.

3. The method of electrically welding metal parts together, which consists in establishing an are between the juxta osed edges of such parts and an electrode 0 high resistance material, moving such electrode along the line of juncture of such edges, and at the same time tilting such parts so that the portion of the line in question under the arc inclines downwardly in the direction of travel of the electrode relatively to the work.

Signed by me this day of June, 1922.

JAMES F. LINCOLN. 

